The present invention relates to the field of treatment of septic tank effluent prior to disposal and, more particularly, to in-line filters for treatment of the effluent.
Conventional drainage fields for land application of septic tank sewage effluent are constructed by digging trenches on land adjoining the septic tank. Filtering beds are created in these trenches by depositing a layer of filtering material in the bottom of the trenches. Conventional filtering material is rock, crushed stone gravel, sand, or a combination thereof. A network of perforated pipe is connected to the septic tank and laid in the trenches on top of the filter bed. Such systems normally operate by gravity flow, however, it is common practice to connect a pump to the septic tank to aid in moving the sewage effluent from the septic tank and through the drainage field, particularly where required by the lay of the land. The sewage effluent is distributed through the network of perforated pipes and trickles onto and through the filter bed, where its nutrient content is reduced by microbial action. After passing through the filtering material, the sewage effluent is absorbed by the soil surrounding and underlying the trench.
Standard practices, however, suffer from severe disadvantages. For example, conventional drainage fields for septic tanks require the transportation of heavy materials, such as the stone, rock gravel or sand required for installing filtration beds. In addition, conventional drainage fields generally operate for years, however, they must be dug up and replaced when they become clogged or otherwise stop functioning as designed. Replacement of the drainage field costs essentially as much as installing a completely new field, and perhaps more.
With the foregoing in mind, the present invention advantageously provides in-line filters for providing treatment for septic tank effluent. The in-line filters may be positioned to treat the effluent before it reaches a conventional drainage field, or may be employed in series as a replacement for the conventional drainage field.
The invention discloses an in-line filtration system for treatment of waste water effluent preferably from a septic tank. A main conduit is connected to a source of waste water, and a filter is positioned within the main conduit. The filter is preferably removable and comprises light weight particulate material, which may preferably be expanded polystyrene, or rubber chips such as from ground tires. The filtering particles are contained in a water permeable sleeve, preferably a mesh, the filter having a handle or other member for aiding in removing the filter from the system.
The system may include an extension conduit connected with the main conduit and extending substantially upwardly therefrom. The extension conduit has a removable cap for providing interior access to the system, such as for removing and replacing filters. The cap comprises a sensor for generating a signal when water in the extension conduit reaches a predetermined level. The sensor may be mechanical or electronic.
The system may additionally include a plurality of filters positioned within the main conduit, the filters comprising light weight particulate material substantially graded in size so as to include relatively larger particles positioned upstream and relatively smaller particles positioned downstream for providing enhanced filtration treatment for the waste water effluent.
The invention also includes a drain field for filtration treatment of waste water effluent, preferably from a septic tank. The drain field comprises a source of waste water effluent, a main conduit connected to the source of waste water, and a plurality of in-line filters positioned within the main conduit, the plurality comprising light weight particulate material to thereby provide filtration treatment for the waste water effluent. The plurality of filters is removable from the system to thereby allow for washing of the filters, or replacement with new filters. The plurality of filters comprises a retrieval member for aiding in removal of the filters, a handle being a preferred retrieval member. The drain field includes at least one extension conduit connected in fluid communication with the main conduit and extending substantially upwardly therefrom. The extension conduit has a removable cap for providing interior access to the system. The cap comprises a mechanical or electronic sensor for generating a signal when water in the extension conduit reaches a predetermined level.
In addition, a method aspect of the invention includes the step of filtering the effluent through a conduit disposed with a removable filter comprising a plurality of filtering particles of light weight material. The conduit of the method may include substantially vertical portions.
Accordingly, the present invention provides various advantages over prior art systems. The invention allows increased filtration of the waste water effluent in less land area. The system provides for progressive filtration before the waste water effluent reaches a conventional drain field, thereby extending the useful life of the drain field. The invention provides for signaling to indicate possible clogging of the system. The system provides easily removable filters, for washing or replacement of the filters. The filters may be made in various sizes to accommodate small and large capacity septic tank waste water treatment systems, and the filters are made of low cost, recycled media.